In recent years, an organic EL (Electro Luminescence) display device that utilizes an organic EL phenomenon to display an image has been attracting attention.
For the organic EL display device, there are a lower surface light emission (bottom emission) system in which light from each organic EL element is emitted to the drive panel side, and an upper surface light emission (top emission) system in which conversely the light is emitted to the sealing panel side. The latter has been the mainstream of development owing to its capability of allowing an aperture ratio to be increased.
Now, in the upper surface light emission system organic EL display device, an electrode on light extracting side, that is, the sealing panel side is an electrode common to each organic EL element, and is configured by a light-transmitting conductive material such as ITO (Indium Tin Oxide). However, such a light-transmitting conductive material has a resistivity which is about 2 to 3 orders of magnitude higher than, for example, an ordinary metal material. Hence, there has been an issue that, since a voltage applied to the electrode on the light extracting side becomes non-uniform within a plane, a positional variation occurs in light emission luminance among each of the organic EL elements and display quality ends up lowering.
Accordingly, the applicant of the present application has disclosed a technique in which a low resistance auxiliary wiring line and the light extracting side electrode are connected via a conductive contact part (refer to Patent Literature 1, for example).